Field of the Invention
The present invention relates to a technique for inserting sheets, a plurality of which form a set.
Description of the Related Art
Conventionally there are printing apparatuses to which multiple types of index sheets can be inserted to print pieces. For example, in the technique disclosed in Japanese Patent Laid-Open No. 2006-248672, different two types of index sheets are stored in trays A and B respectively and the printing apparatus inserts the index sheets in the tray A and the index sheets in the tray B to each of copies. The printing apparatus, when not using all index sheets included in a set, discharges the remaining index sheets from the trays A and B at the point of finishing outputting each of the copies.
Although in Japanese Patent Laid-Open 2006-248672 the two different types of index sheets are used those index sheets cannot be used in a hierarchical manner. Especially, when not all index sheets included in a set are used i.e., if some index sheets are left unused), the multiple types of the index sheets cannot be used in a hierarchical manner.
For example, it is assumed that a first type of index sheet is a higher layer (e.g., for separating chapters) and a second type of index sheet is a lower layer (e.g., for separating sections), and one set of the second-type index sheet includes N sheets. After the first sheet of the first-type index sheet is output, the first to Mth sheets of the second-type index sheets are output (M<N) (e.g. a single chapter contains M sections). In this case, (N−M) sheets of the second-type index sheet are left on the tray. Accordingly, when the second chapter of the document begins next, it is impossible to output a second sheet of the first-type index sheets and then output the second-type index sheets inserted from the beginning of the sections of the second chapter.